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Comparison of organochlorine pesticides and PCB residues among hawksbill (Eretmochelys imbricata) and green (Chelonia mydas) turtles in the Yucatan Peninsula and their maternal transfer Texte intégral
2015
García-Besné, Gabriela | Valdespino, Carolina | Rendón-von Osten, Jaime
Organochlorine pesticides and PCB (POPs) concentrations were determined in the blood and eggs of green and hawksbill turtles. We compared concentrations between species, analyzed the relationship between turtle size and the POPs concentrations and the relationship between the concentrations in the blood of the nesting turtles and their eggs. We expected higher concentrations in the hawksbill turtle because of its higher trophic level, but concentrations were not higher in all the cases. Significant differences were found in δ-HCH blood concentrations. Lindane, heptachlor epoxide and PCB 101 concentrations were significantly higher in the hawksbill eggs. The relationship between the size of the turtles and the POP concentrations in the eggs of the hawksbills showed a negative correlation. No correlation was found between the size of the female and concentrations in the blood. In eggs, only the hawksbill turtles exhibited negative correlation in the concentration of mirex and PCB 44 and size.
Afficher plus [+] Moins [-]Highly recyclable superhydrophobic sponge suitable for the selective sorption of high viscosity oil from water Texte intégral
2015
Wang, Jintao | Geng, Guihong
Inspired by the adhesion of marine mussels, a kind of superhydrophobic oil sorbent was successfully fabricated by robustly immobilizing the micro/nanostructure layer onto the sponge skeleton. The as-prepared sponges possess excellent hydrophobicity with the water contact angle of 154°, which enables the sponge to selectively absorb various oils floating on water surface. The oil sorption capacities of as-prepared sponge for a series of oils can reach 18.3–46.8g/g. The absorbed oil can be recovered by mechanical squeezing and the resulting sponge can be recycled more than 70 cycles while still keeping high oil sorption capability. More importantly, the obtained sponge has excellent affinity to the high viscosity oils. Therefore, the as-prepared sponge might find practical applications in the large-scale removal of oils especially high viscosity oils from water surface.
Afficher plus [+] Moins [-]Anthropogenic influence on sediment transport in the Whittard Canyon, NE Atlantic Texte intégral
2015
Wilson, Annette M. | Kiriakoulakis, Kostas | Raine, R. (Robin) | Gerritsen, Hans D. | Blackbird, Sabena | Allcock, A Louise | White, Martin
Unusual peaks in turbidity were detected in two branches of the Whittard Canyon in June 2013. Enhanced nepheloid layers (ENLs) were defined as layers with concentrations of suspended particulate matter exceeding those of nepheloid layers typically observed in a given region. Here, ENLs had peaks in turbidity and elevated suspended particulate matter concentrations exceeding ~1mgL−1 with the largest ENLs measuring between ~2–8mgL−1. The ENLs measured ~100–260m in vertical height and were detected in water depths of between 640 and 2880m. Vessel Monitoring System data showed that high spatial and temporal activity of potential bottom trawling vessels coincided with the occurrence of the ENLs. Molar C/N ratios of the suspended organic material from the ENLs showed a high degree of degradation. Regular occurrences of such events are likely to have implications for increased sediment fluxes, burial of organic carbon and alteration of benthic and canyon ecosystems.
Afficher plus [+] Moins [-]Nickel and chromium concentrations in Italian ryegrass exposed to ambient air in urban, suburban and rural areas Texte intégral
2015
Budka, Anna | Borowiak, Klaudia | Kayzer, Dariusz | Hanć, Anetta | Zbierska, Janina | Barałkiewicz, Danuta | Wolna-Maruwka, Agnieszka | Lisiak, Marta
Nickel and chromium accumulation from the air in Italian ryegrass (Lolium multiflorum L.) is presented in this paper. Plants were exposed at five sites varying in environmental characteristics. Four one-month series were performed during the 2011 and 2012 growing seasons. Chromium and nickel concentrations in leaves were analysed after every series and compared to control plants. The lowest levels of both trace elements were found in samples collected from control sites. Canonical variate analysis revealed differences among sites and the control, and on this basis we found the lowest values in the suburban area. The lowest trace element concentrations of Cr in leaves were observed at the beginning of the growing season and the highest from mid-June to mid-August, while Ni concentrations varied among series and years. Accumulation of both trace elements in Italian ryegrass was at a comparable level or lower than results obtained in similar investigations in other countries. Moreover, the higher concentrations of both elements were probably connected with increased traffic and elevated small industry activities in urban and rural areas.
Afficher plus [+] Moins [-]Tempting long-memory in the historic surface ozone concentrations at Athens, Greece Texte intégral
2015
Varotsos, Costas | Tzanis, Chris | Efstathiou, Maria | Deligiorgi, Despina
The intrinsic features of the temporal evolution of the air pollution are of crucial importance for its reliable modeling. In this regard, Varotsos et al. (2012) suggested that the surface ozone fluctuations at Athens since 1900, exhibit long-range dependence (long-memory), despite its present-day doubling. We herewith establish the long-memory in surface ozone concentrations that assumed in Varotsos et al. (2012), by employing recent analytical tools.
Afficher plus [+] Moins [-]on–road measurement of gaseous emissions and fuel consumption for two hybrid electric vehicles in Macao Texte intégral
2015
Wu, Xiaomeng | Zhang, Shaojun | Wu, Ye | Li, Zhenhua | Ke, Wenwei | Fu, Lixin | Hao, Jiming
Hybrid electric vehicles (HEVs) are promoted in China to ease increasing pressures of urban air pollution and oil security. In this paper, we measured two Toyota Prius HEVs by using a portable emission measurement system (PEMS) to evaluate their real–world performance with regard to gaseous emission factors and fuel consumption. Our results indicated that their average exhaust emission factors of CO, THC, NOX and CO2 were 0.25±0.08 gkm–1, 0.015±0.002 gkm–1, 0.009±0.005 gkm–1 and 136±21 gkm–1 (i.e., 5.81±0.90 L 100km–1 for fuel consumption) respectively, while driving the averaged on–road traffic pattern. Compared to conventional gasoline and diesel vehicles, the tested HEVs demonstrated significant advantages in simultaneously mitigating major air pollutants (e.g., NOX), greenhouse gas emissions (CO2) and fuel consumption. For example, average CO2 emission factors are reduced by approximately 35% and 15% relative to conventional gasoline and diesel cars in Macao. Unlike conventional gasoline and diesel cars, relative CO2 emission factors of HEVs were much less sensitive to speed change, while their relative NOX emission factors were reduced as average speed became lower. This indicates significant environmental and energy benefits from HEVs under congested driving conditions. Our assessment suggests that HEVs are a competitive technology option for the taxi fleet in Macao with strong advantages in saving fuel cost for taxi drivers and mitigating NOX emissions.
Afficher plus [+] Moins [-]Trace element composition of PM2.5 and PM10 from Kolkata – a heavily polluted Indian metropolis Texte intégral
2015
Das, Reshmi | Khezri, Bahareh | Srivastava, Bijayen | Datta, Subhajit | Sikdar, Pradip K. | Webster, Richard D. | Wang, Xianfeng
Elemental composition of PM2.5 and PM10 was measured from 16 locations in Greater Kolkata in Eastern India. Sampling was carried out in the winter months of 2013–2014. PM2.5 and PM10 mass concentrations ranged from 83–783μg/m3 and 167–928μg/m3 respectively. 20 elements were measured with an Agilent 7700 series ICP–MS equipped with a 3rd generation He reaction/collision cell following closed vessel microwave digestion. In both size fractions Fe, Na, Al, K, Ca were present in high concentrations (>1 000ng/m3), Mn, Zn and Pb demonstrated medium concentrations (>100ng/m3), and Sc, V, Co, Ni, Mo, Cd, Sn and Sb had low concentrations (<100ng/m3). Ca, Al, Mg, Sc, Ti, Mn and Fe were concentrated in the PM10 fraction, while the toxic metals (Cr, Ni, Zn, Mo, Sn, Sb, V, Co, Cu, Cd and Pb) were concentrated in the PM2.5 fraction. Al normalized Enrichment Factors (EF) showed EF<10 for Ti, Mg, Sc, Fe, Mn, Na, K, Ca, V, Co which is indicative of crustal sources, 100>EF>10 for Ni, Cr, Cu is possibly industrial influence and 1 000>EF>100 for Sn, Zn, Mo, Sb, Pb, Cd is related to industrial, high temperature combustion and vehicle sources. Factor analysis identified three possible sources for PM10; (1) abraded vehicular part related road dust, exhaust gases of car and municipal waste incineration (2) industrial emissions, and (3) coal combustion and non–ferrous metal smelting and three possible sources for PM2.5; (1) abraded vehicular part related road dust and industrial emissions (2) exhaust gases of cars and municipal waste incineration, and (3) coal combustion and non–ferrous metal smelting. In a risk evaluation using a U.S. EPA IRIS, chromium was found to have the highest excess cancer risk.
Afficher plus [+] Moins [-]Physiological perturbations in juvenile cuttlefish Sepia officinalis induced by subchronic exposure to dissolved zinc Texte intégral
2015
Le Pabic, Charles | Caplat, Christelle | Lehodey, Jean-Paul | Dallas, Lorna | Koueta, N. (Noussithé)
Although cephalopod early life stage development often occurs in coastal areas where contamination is real and continuous, the physiological perturbations induced by contaminants have been rarely investigated. This study focused on the Zn as it is one of the trace metals the most concentrated in coastal waters, worldwide. As Zn-tolerance limits were unknown in juvenile Sepia officinalis, the aim of this study was to estimate the threshold inducing mortality during the 2-first weeks post-hatching, and to determine its sensitivity using digestive and immune enzymatic assays, as well as growth and behavior follow-up during the first 5weeks post-hatching. Our study highlighted a Zn-mortality threshold lying between 185 and 230μgl−1, and growth reductions occurring after 5-week at 108μgl−1 and above, associated with enzymatic perturbations. These results underline a relatively important sensitivity of juvenile cuttlefish to Zn, pointed out by a wide diversity of biomarkers.
Afficher plus [+] Moins [-]Spatial distribution, sources and ecological risk assessment of polycyclic aromatic hydrocarbons in surface seawater from Yangpu Bay, China Texte intégral
2015
Li, Ping | Cao, Jia | Diao, Xiaoping | Wang, Bohua | Zhou, Hailong | Han, Qian | Zheng, Pengfei | Li, Yuhu
The occurrence of 14 polycyclic aromatic hydrocarbons (PAHs) listed by the United States Environmental Protection Agency was investigated in surface seawater of Yangpu Bay, China in November 2013 (winter) and May 2014 (summer). Seventy-two samples were collected from 12 sampling sites. The total concentrations of PAHs in Yangpu Bay showed obvious variations in different seasons, which varied from 582.8 to 2208.3ngL−1 in winter and 952.4 to 1201.7ngL−1 in summer, respectively. Two-ring PAHs accounted for more than 91.6% of total PAHs in winter, and three-ring PAHs were dominant with 81.6% of total PAHs in summer. Molecular indices analyses indicated that the main source of PAHs in Yangpu Bay could be petrogenic contamination. The ecological risk assessment by Risk quotients (RQNCs and RQMPCs) showed a potential ecological risk of PAHs in Yangpu Bay, indicating a close attention should be paid to pollution of PAHs in the coastal area of Yangpu.
Afficher plus [+] Moins [-]Tissue-specific Cd and Pb accumulation in Peruvian scallop (Argopecten purpuratus) transplanted to a suspended and bottom culture at Sechura Bay, Peru Texte intégral
2015
Loaiza, Iván | Hurtado, Daniela | Miglio, Maria | Orrego, Henry | Mendo, Jaime
In order to understand the effect of different culture systems on Cd and Pb accumulation, suspended long-line and bottom cultures of Argopecten purpuratus were conducted during January until April 2010 (120days). The Cd tissue levels were the highest at the middle of the experiment (30-d till 70-d) for suspended-cultured individuals, while bottom-cultured individuals showed an increasing trend. Gonad Pb levels were also higher during the same period for all cultures, while adductor muscle exhibited no considerable variations. Cd and Pb tissue concentrations were mainly greater in deeper cultures. There were no significant differences in Cd and Pb accumulation between individual sizes. The Cd and Pb levels in edible tissue (gonad+adductor muscle) did not exceed the EU and FDA maximum levels. Based on the target hazard quotient (THQ) and the provisional tolerance weekly intake (PTWI), no risk (THQ<1 and %PTWI<30) was found for human consumption.
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